Interesting ImagesMetastatic Parathyroid Hormone-Secreting Prostate Adenocarcinoma Mimicking Ectopic Parathyroid Adenoma Demonstrated on 99mTc-MIBI ImageChen, Yu-Hung MD∗; Hsu, Yung-Hsiang MD†; Chen, Hwa-Tsung MD‡; Chang, Bee-Song MD§; Liu, Shu-Hsin MD∗,∥Author Information From the Departments of ∗Nuclear Medicine †Pathology ‡Surgery §Thoracic Surgery, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation ∥Department of Medical Imaging and Radiological Science, Tzu Chi University of Science and Technology, Hualien, Taiwan. Received for publication December 12, 2019; revision accepted March 12, 2020. Conflicts of interest and sources of funding: none declared. Correspondence to: Shu-Hsin Liu, MD, Department of Nuclear Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, 707 Section 3, Chung-Yang Rd, Hualien, 97002, Taiwan. E-mail: email@example.com. Clinical Nuclear Medicine: July 2020 - Volume 45 - Issue 7 - p 555-556 doi: 10.1097/RLU.0000000000003064 Buy Metrics Abstract 99mTc-MIBI has long been used to localize hyperfunctioning parathyroid tissue in patients with hyperparathyroidism. This tracer can also concentrate in various neoplastic tissues including prostate adenocarcinoma. We herein report a case with parathyroid hormone-secreting metastatic prostate cancer mimicking an ectopic parathyroid adenoma on the 99mTc-MIBI scan. We conclude that metastatic prostate cancer should be included as one of the differential diagnoses when interpreting 99mTc-MIBI scan. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.